Stop unwanted calls and texts from hitting your cellphone

You may find this surprising. Many of us remember when people's names, addresses and phone numbers were listed in the telephone book and distributed for free. All we ever worried about were junk mail, telemarketers and the occasional prank call.

Times have changed. Phone books are now history. You can message anyone you know (or don't) on Facebook, Twitter or other means. And most importantly, your phone number is a gateway to your primary means of communication, entertainment and safety. Once your number is compromised, it's far more intrusive than ever before.

Spam texts and robocalls

Every year or so, a hoax burns like a wildfire through email inboxes and social networks warning that all cellphone numbers are about to go public. It also says there's a deadline to register your cellphone and, once registered, it only blocks your number for five years.

Oddly enough, the only thing the hoax message gets right is the number to call. For the record, mobile telephone numbers have never been in any danger of being made public or released to telemarketers. Additionally, there has never been a deadline to register your cellphone. And you don't need to renew every five years (this was a rule for landlines that was axed in 2007).

If you get an unsolicited marketing call on your cellphone, first ask the caller how they got your number and firmly tell them you don't want to be contacted again. If they call back, file a complaint with the FTC at donotcall.gov or 1-888-382-1222.

But these days, many companies find it cheaper, easier and more profitable to send advertisements by text.

You may also receive a host of "robocalls," pre-recorded messages that automatically play when you pick up. With so many cellphone numbers being collected in databases, companies have a massive list of potential customers.

People know it is you calling when your caller ID pops up on their phone, but it doesn't have to be like that. There are two ways to keep your identity secret while making a call: one is permanent, the other is temporary on a call-by-call basis.Here's a tip that covers both methods.

When you receive an unwanted solicitation by phone, you may wonder: How did they get my number? You've only given it to friends. You haven't posted your number on social media. You barely use your phone to make calls anymore. So what gives?

People hand over their numbers often without even realizing it. When you install a new app, you receive a lengthy "terms of service" document. Buried in that fine print, there is often a clause about releasing your number to third parties. By accepting these terms of service, you typically give the company permission to use or sell your cellphone number.

For example, PrivacyGrade took a look at the Brightest LED Flashlight app and found it can read the phone's current state information like phone signal, carrier, device ID and phone number. Before you install an app, take a moment to learn exactly what information the app is collecting and how the developers intend to use the data.

Many people are careless on Facebook, giving criminals heaps of personal information without a second thought. They post their birthdays and home addresses, and they even indicate when they're home or away.

Putting your cellphone number on social media can be hazardous, especially if you have a lot of "friends" who you don't know in real life. You may have tight privacy settings, but if you agree to be friends with a stranger, your data could be easily copied and pasted into nefarious hands.

Use your thinking cap. You may find it easy to find volunteers for your upcoming benefit by posting your cell number on Twitter. You may take a picture of your "Missing Dog" sign and post it on Instagram. But the short-term benefits aren't worth the potential data breach.

Phone numbers and security verification

Password? Check. Secret security question? Check. Phone number?

More and more, secure websites are using your phone number to verify your identity. If you have an Amazon, Facebook, Google, Microsoft or Apple account, give them your cellphone number in your security settings. This way, if someone signs into your account using a new device or location, you receive an immediate alert.

In addition, you can also receive an alert if someone tries to change your password. If a hacker steals your password and tries to log in to your account on an unknown computer, the site will ask them for the second code. Unless the hackers also stole your phone and were able to unlock it, they would not have the second code needed to log in.